Thus, to prove Lemma REF , it is sufficient to show that \(|f_{i,j}|\le c_1Q^2/(q^3mn)\)  for any \(i,j\) .
The condition \(m/n=O(1)\)  guarantees that \(Q/q=o(m)\)  if \(Q/q=o(n)\) .
The remainder of the proof of Lemma REF  is similar to the proof of Proposition 1 in [1]}, and we omit the details here.
